The present invention relates to a copying machine capable of copying an irregular-sized document onto regular-sized copy paper in variable magnifications, and specifically relates to a copying machine capable of changing the picture position when a blank is produced in the direction the copy paper is fed.
In recent years, as copying machines have become increasingly multi-functional, providing among other things, a function to copy an irregular-size document onto irregular-sized copy paper in variable magnifications.
This machine detects or inputs the lengths of the longitudinal and lateral sides of an irregular-sized document by a detecting apparatus on the document table or an inputting apparatus on an operating part to store them in a RAM, and also reads out the set length of each side of copy paper from a ROM storing the usable regular sizes in advance, working to the ratio of the longitudinal and lateral lengths of both. Furthermore, this machine compares the ratio of the longitudinal sizes with the ratio of the lateral sizes to select the ratio of smaller numeric value as the magnification to employ. For example, as shown in FIG. 1, where an irregular-sized document 1 having a length of a=150 mm and width of b=100 mm is copied in a variable magnification fashion onto A4 size copy paper, 297 mm.times.210 mm, by feeding the copy paper in the direction shown by arrow A, the longitudinal ratio is 297.div.150=1.98, and the lateral ratio is 210.div.100=2.1. In this case, ratio 1.98 is employed as the magnification ratio, and, as shown, on copied paper 2', a picture is formed in the longitudinal direction. In the lateral direction, a picture of 198 mm, the product of the length of the lateral side of the document, 100 mm, and the magnification ratio of 1.98, is formed.
However, in conventional copying machines, the timing relationship of feeding the copy paper to starting the operation of the copying machine, is always constant. That is, the copy paper is fed to the copying apparatus so that the position of the picture at the front end portion of the document table in the direction of copy paper feeding will coincide, in the copying apparatus, with the front end of the copy paper in the direction of feeding. For this reason, in FIG. 1, document 1 is copied in such a manner that the front end portion 1a of the document 1 coincides with the front end portion 2a of the copy paper 2, and, as shown in the copied paper 2', a blank portion 3 of 210 mm-198 mm=12 mm is produced at the rear. This blank portion 3 is always produced when the longitudinal ratio is selected as the magnification ratio as described above, being produced at the rear portion of the copy paper in the direction of feeding the copy paper. For this reason, the paper copied in the above-described situation suffers the disadvantages that the picture position always deviates, resulting in non-legibility of the contents and part of the picture being sometimes hidden behind the binder part of the file when filing. In order to eliminate such disadvantages of conventional copying machines, the document is moved backward the requisite distance from the normal reference position when setting the document on the document table. Also, a troublesome calculation is required to accurately calculate the distance the document is to be moved, Otherwise, small movements may have to be repeated until the optimum copying position is reached, but this results in many failed copies and waste. In either case, the copying operation takes a long time and is also troublesome, thereby having the disadvantage of appreciably reducing the running efficiency of the copying machine.